Jira user creation via REST results in 401 - This resource requires WebSudo - powershell

Question

I'm attempting to write a PowerShell script that will automate the process of adding new user accounts to our Jira instance. I've provided my code but I'm honestly not even getting to that point as I am receiving a 401 error:
This resource requires WebSudo.
I have seen these two posts on the Jira support forum but it's not clear to me how I could adapt the code to get and then apply it to my REST call. I would be fine with changing this to use the .Net WebClient class if that would make all of this easier, but right now I'm at a bit of a loss.
$url = "https://devjira.domain.com/rest/api/2/user"
$user = "admin"
$pass = "super secure password"
$secpasswd = ConvertTo-SecureString $user -AsPlainText -Force
$cred = New-Object System.Management.Automation.PSCredential($pass, $secpasswd);
$userObject = #{
name = "rkaucher#domain.net";
emailAddress = "robert_kaucher#domain.com";
displayName = "Bob Kaucher";
notification = $true;
}
$restParameters = #{
Uri = $url;
ContentType = "application/json";
Method = "POST";
Body = (ConvertTo-Json $userObject).ToString();
Credential = $cred;
}
Invoke-RestMethod #restParameters
JSON output
{
"name": "rkaucher#domain.net",
"displayName": "Bob Kaucher",
"emailAddress": "robert_kaucher#domain.com",
"notification": true
}

Answer 1

I changed the authentication component of my script to this:
$cred = [Convert]::ToBase64String([Text.Encoding]::ASCII.GetBytes("$user`:$pass"))
$headers = #{Authorization=("Basic $cred")}
This was based on the selected answer to the following:
PowerShell's Invoke-RestMethod equivalent of curl -u (Basic Authentication)
The final invocation of the method looks like this:
$restParameters = #{
Uri = $url;
ContentType = "application/json";
Method = "POST";
Body = (ConvertTo-Json $userObject).ToString();
Headers = $headers;
}
$response = Invoke-RestMethod #restParameters